Source : Webster's Revised Unabridged Dictionary (1913)

Purslane \Purs"lane\, n. [OF. porcelaine, pourcelaine (cf. It.
   porcellana), corrupted fr. L. porcilaca for portulaca.]
   (Bot.)
   An annual plant ({Portulaca oleracea}), with fleshy,
   succulent, obovate leaves, sometimes used as a pot herb and
   for salads, garnishing, and pickling.

   {Flowering purslane}, or {Great flowered purslane}, the
      {Portulaca grandiflora}. See {Portulaca}.

   {Purslane tree}, a South African shrub ({Portulacaria Afra})
      with many small opposite fleshy obovate leaves.

   {Sea purslane}, a seashore plant ({Arenaria peploides}) with
      crowded opposite fleshy leaves.

   {Water purslane}, an aquatic plant ({Ludwiqia palustris}) but
      slightly resembling purslane.

Source : WordNet®

purslane
     n : a plant of the family Portulacaceae having fleshy succulent
         obovate leaves often grown as a potherb or salad herb; a
         weed in some areas